Trip movement for watchmen&#39;s patrol boxes



Sept. 19, c ENGELMANN I TRIP MOVEMENT FOR WATCl-IMENS PATROL BOXES FiledJuly 28, 1949 Ernesi 1711996741 (3717? Patented Sept. 19, 1950 THU?MOVEMENT FOR WATCHMENS PATROL BOXES Ernest C. Engelmann, Arlington, Va.

Application July 28, 1949, Serial No. 107,355

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 2 Claims.

The invention described herein may be manufactured and used by or forthe Government of the United States for governmental purposes withoutpayment to me of any royalty thereon in accordance with the provisionsof the act of April 30, 1928 (ch. 460, 45 Stat. L. 467).

The invention relates to a device for use with the present key operatedmovement on night watch patrol boxes, and particularly to a collar andstop plate which protects the mechanism against damage which may resultfrom the use of excessive force in turning the guards key.

In the accompanying drawing which illustrates a preferred form of myinvention:

Figure 1 is a side elevation showing a mechanism for tripping anelectric switch by means of a manually operated key including theapplicants novel collar and stop plate.

Figure 2 is a side elevation showing the applicants novel collar andstop plate turned by a key (not shown) to registering position.

Figure 3 is a section on the line 3-3 of Figure 1.

In these drawings, Hi represents a key stem provided with a transversehole for a pin it adapted to trip a lever l2 which in turn serves as ameans for tripping an electric switch in a signaling circuit (notshown). The key stem is provided with a squared end 13 which is adaptedto be operatively connected with a watchmans key having a coactingrecess. My novel collar M is provided while a stop plate i5 integralwith the collar [4 has apertures for the pin H, with an arcuate slot Itfor a stop pin 5 l of the original device and with a hole adjacent itsouter end for receiving a coiled tension spring is of the originaldevice.

The applicants attachment involves no major alterations of the presentdesign, not illustrated, it being necessary merely to pull the originalpin II out of the stem Iii, slip the collar [4 over the stem H] with thetransverse apertures in alignment with the hole in the stem it and thestop pin H in the arcuate slot 16 thread the pin ll through the stem I0and collar 14, then attach the tension spring [8 to the stop plate 15instead of the pin 1 I. It may be necessary to cut off an excess of theoriginal pin II when altering the original movement by the combinationwith the novel collar and stop plate.

Force applied by the watchman through his key to the squared end l3 ofthe stem It is transmitted as a shearing force to the applicants collarI4 through the oppositely extending parts of the pin I l to the widestop plate IE to the original 2 stop pin l1. With the present design(not illustrated), the application by a Watchman of excesive forcethrough his key causes that part of the present longer pin l I whichengages the stop pin I! to either bend or break, thereby disconnectingthe spring l8 from the originally longer pin l I so that the switch isno longer returned to it initial position after each key operation. Theapplicant substitutes for a portion of the original pin II the stopplate which is sufiiciently wide in a plane perpendicular to the axis ofthe key stem H) to provide ample strength to resist any stress which maybe applied through a watchman key.

It should be understood that the present disclosure is for the purposeof illustration only, and that the invention includes all modificationsand equivalents which fall Within the scope of the appended claims.

What is claimed is:

1. In a night watch patrol box provided with a key operated trippingmechanism the improvement which comprises a key stem enclosing collarprovided with two transverse apertures which are aligned with atransverse aperture in said stem, a stop plate integral with said collarand provided with an arcuate slot for a stop pin and an aperture forattaching a tension spring, whereby said mechanism is protected againstdamage due to excessive force applied by a key to said stem.

2. In a patrol box provided with a key operated circuit making andbreaking mechanism, the improvement which comprises an enclosing collarfor a transversely apertured key stem said collar being provided withtwo aligned transverse apertures for receiving a pin, a stop plateintegral with said collar which provides two limiting stops for a stoppin and means for attaching a tension spring.

ERNEST C. ENGEIMANN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,637,520 Dodge Aug. 2, 19272,115,849 Gustavson May 3, 1938 2,351,172 White June 13, 1944 FOREIGNPATENTS Number Country Date 3,489 Great Britain Feb. 11, 1902

